This invention relates to medical drainage pouches, and, more particularly, to an improved sealing assembly for such drainage pouches, which include surgical pouches for stoma or wound drainage, fecal collectors, enema bags, urostomy bags, etc.
Certain surgery, such as abdominal surgery known as colostomy, ileostomy, ureterostomy and the like, results in an opening, for example, in the abdominal wall, which permits drainage from the interior of a body cavity. The patient cannot control the drainage, and therefore a surgical drainage appliance in the form of a pouch or bag is used to contain the drainage.
U.S. Pat. Nos. 3,302,647 and 3,822,704 disclose prior art surgical drainage pouches, as used particularly for stoma or wound drainage. Each of these pouches includes a plastic bag for containing the fluid which is drained from the body and a relatively rigid plastic retainer ring which is heatsealed to the bag around the drainage opening in the bag. The drainage pouch described in U.S. Pat. No. 3,302,647 includes a sealing pad or ring formed from a mixture of karaya powder and glycerol. The drainage pouch described in U.S. Pat. No. 3,822,704 includes an adhesive patch which is secured to the relatively rigid retaining ring. A release paper covers the adhesive surface of the adhesive patch, and when the release paper is removed, the adhesive patch can be adhesively secured to the patient's body.
Current commercial surgical drainage pouches are similar to the pouch described in U.S. Pat. No. 3,822,704. The adhesive patch is formed from a nonporous surgical adhesive tape. This tape may comprise a backing sheet of nonporous polyethylene coated with a layer of pressure-sensitive adhesive. The relatively rigid retainer ring can be formed of polyethylene, and the adhesive patch secured to the retainer ring by heat-sealing the polyethylene backing of the adhesive patch to the polyethylene retainer ring. Alternatively, the nonporous adhesive patch can be heat-sealed directly to the pouch around the opening.
Drainage pouches which are provided with such a nonporous polyethylene adhesive patch are sold with and without a karaya sealing ring of the type described in U.S. Pat. No. 3,302,647. The adhesive patch is much larger than the karaya sealing ring, which is intended to seal the area adjacent the stoma against irritating fluids. The adhesive patch is adhesively secured to the body radially outwardly of the karaya ring to provide additional mechanical securement.
While such nonporous adhesive patches provide good adhesive and mechanical securement, certain problems have arisen. Since polyethylene or similar patches are not porous, the skin cannot breathe through the patch. The patch traps moisture against the skin and might cause an increase in the skin irritation of the patient.
Porous non-woven surgical adhesive tape is available. For example, a porous non-woven surgical tape is available under the brand name "Micropore" from Minnesota Mining & Manufacturing Company, of Minneapolis, Minn. This tape is formed from a backing layer of porous, non-woven rayon fabric and a layer of hypo-allergenic, synthetic, acrylic pressure-sensitive adhesive. Such tape is essentially continuous in appearance and is non-perforated but exhibits a porosity which permits the skin to breathe through the tape. Because the pores of the tape are quite small and the tape appears to be essentially continuous, the tape is considered microporous.
Our attempts to substitute a porous non-woven surgical adhesive tape for the polyethylene adhesive patch on the drainage pouch were initially unsuccessful. First of all, the non-woven fabric backing layer of the tape cannot be satisfactorily heatsealed directly to the plastic retainer ring or to the pouch. We found that some other means of attaching the fabric backing to the retainer ring must be used. We also found that the very thin non-woven fabric is very easily torn at any concentrated stress point. For example, the fabric is easily tearable when it is subjected to a force tending to peel it away from an area of attachment or when it is subjected to a force which is directed angularly with respect to the plane of the fabric. Since the drainage pouch fills with fluid and becomes quite heavy, the force which tends to peel the retainer ring away from the adhesive patch which secures the pouch to the skin can become substantial and tear the patch causing leakage.